Method and apparatus for vacuum filling open mouth bags

ABSTRACT

A filling assembly for vacuum filling impervious open mouth paper bags with finely divided particulate material. A filling head is provided with at least two independent vertically extending chambers through which a selective vacuum or relief may be applied. Particulate material is fed through a central opening in the filling head whereby interstitial air is withdrawn from between the particles of particulate material as the material falls downwardly into an impervious open mouth bag. Clamping jaws serve to seal the bag against the filler head during the filling operation and include clamping flanges which extend outwardly from the jaws and tightly close the outer edges of the open mouth bag. A shroud extends from the clamping jaws to provide a sealed enclosure about the bag during the vacuum filling operation. A vacuum source is selectively applied to the shroud to open the impervious bag and keep the bag open during the vacuum filling operation.

United States Patent [191 [111 3,785,410 Uarter Jan. 15, 1974 METHOD AND APPARATUS FOR VACUUM Prima ry Exam inerHouston S. Bell, .lr.

FILLING OPEN MOUTH BAGS [75] Clarence F. Carter, Danville, Ill.

Inventor:

Assignee: Carter Engineering Company,

Filed:

Appl. No.:

[56] References Cited UNITED STATES PATENTS Fox 141/316 Carter 141/10 A ttor'ney- Burns, Doane, Swecker 8L Mathis 57 ABSTRACT A filling assembly for vacuum filling impervious open mouth paper bags with finely divided particulate material. A filling head is provided with at least two independent vertically extending chambers through which a selective vacuum or relief may be applied. Particulate material is fed through a central opening in the filling head whereby interstitial air is withdrawn from between the particles of particulate material as the material falls downwardly into an impervious open mouth bag. Clamping jaws serve to seal the bag against the filler head during the filling operation and include clamping flanges which extend outwardly from the jaws and tightly close the outer edges of the open mouth bag. A shroud extends from the clamping jaws to provide a sealed enclosure about the bag during the vacuum filling operation. A vacuum source is selectively applied to the shroud to open the impervious bag and keep the bag open-during the vacuum filling operation.

PMENIEU A 3.785410 SHEET 2 BF 3 FWE PATENTEDJAN v 5.914

SHEET .3 UP 3 METHOD AND APPARATUS FOR VACUUM FILLING OPEN MOUTH BAGS BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for filling receptacles with finely divided particulatematerial. More particularly, the invention relates to a ing gusset like edges with particulate material.

Filling receptacles with finely divided particulate material has been and continues to be a difficult and challenging area of technology. In this connection, finely divided material is often difficult to feed and compact within a container. Moreover, fine material that escapes during a filling operation tends to remain suspended in the atmosphere around the filling equipment and thus serves as a major discomfort to operational personnel. i

Notwithstanding, however,.t he above noted difficulties, advances have been made with respect to filling techniques in relation to varioustype receptacles. For example, vacuum filling techniques have been successfully utilized to fill rigid barrels, boxes, impervious open mouth bags, impervious valved bags, etc.

Recently, increased attention has been focused on flexible receptacles which provide a maximum degree of seal integrity while simultaneously being highly economical to manufacture. A container which has been found to meet these requirements comprises an open mouth paper bag having gusset like edges with foldover heat sealable ends. Previous to applicants subject invention, however, the art has failed todisclose a device which may be effectively utilized to vacuum fill such an open mouth impervious paper bag.

In this connection, while devices such as disclosed in applicants U.S. Pat. No. 2,815,621 may be advantageously utilized with stretchable bags, paper bags have very little ability to stretch, and thus tend to tear and present difficult handling problems. Devices which have been particularly designed to fill valved bags, such as disclosed in applicants US. Pat. No. 2,765,816, have proven to be unsuitable for filling open mouth paper bags. Moreover, devices which have been successfully and advantageously utilized to fill boxes and bags, such as applicants US. Pat. No. Re. 23,504, have also proven to be unsatisfactory for filling paper bags having gusset like edges.

It would therefore be highly desirable to provide a vacuum filling apparatus whichv may be utilized to fill an open mouth paper bag with finely divided particulate material. lt would further be desirable to provide a vacuum filling apparatus which may be utilized to fill an open mouth paper bag having gusset type edges.

OBJECTS AND SUMMARY OF THE lNVENTlON It is a general object of the invention to provide a method and apparatus which will obviate or minimize the problems of the type previously described.

It is a particular object of the invention to provide a novel method and apparatus suitable for vacuum filling flexible, impervious, open mouth paper bags.

It is another object of the invention to provide a novel clamping shroud for holding the open mouth of an impervious paper bag against a filling head and for simultaneously providing a sealed shroud about the bag.

It is yet another object of the invention to provide a novel clamping shroud for vacuum filling gusset type paper bags. 7

It is a further object of the-invention to provide a novel method and apparatus for circumferentiallyclamping a paper bag against a filling head.

It is still a further object of the invention to provide a novel method and apparatus for clamping an open mouth paper bag having gusset like edges against a filling head while minimizing stress on the bag at a position adjacent the clamped edges of the bag and the filler head.

An embodiment of the invention suitable to accomplish at least some of the foregoing objects comprises a generally elliptical shaped vacuum filler head having a material feeding conduit extending therethrough. The conduit feeds pulverulent material into a central opening within the head and between two chambers through 'which vacuum and relief pressures are applied. These chambers communicate with the central openin g of the filler head by means of a perforated plate and backing screen.

A clam-type shroud is connected to the filler head and includes clam shell halves vertically pivotable about a generally horizontal axis to a closed position. The upper periphery of the clam-type shroud includes clamping jaws which, when closed, hold the open mouth of a bag against the outer periphery of the filler head. Flanges extending outwardly from the jaws serve to depress gusset type edges of the bag together. Additionally, a vacuum may be selectively applied to the shroud about the bag to keep it in an open posture during the vacuum filling operation.

In another embodiment of the invention, the shroud halves close linearly about a filler head having a vertically positioned material inlet, vacuum line and vacuum relief line. A support platform moves upwardly to hold the bottom of the bag and serves as a lower seal for the linear shroud arrangement. Clamping jaws on the upper periphery of the shroud engage the filler head and the gusset type end portions of the bag.

THE DRAWINGS Other objects and advantages of the present invention will become apparent from the subsequent detailed description thereof when taken in conjunction with the accompanying drawings wherein like numerals designate like elements, and in which:

FIG. 1 is a perspective view of a vacuum filler assembly illustrating an open mouth bag clamped into position for vacuum filling;

FIG. 2 is a cross-sectional view of the filler head and clamping shroud of the invention taken along section line 2--2 of FIG. 1;

FIG. 3 is a cross-sectional view of the filler head and shroud assembly taken along line 3-3 of FIG. 1;

FIG. 4 is an operational view of the shroud assembly in an open clamping position; FIG. 5 is a perspective view of a paper bag having gusset type edges;

FIG. 6 is an edge view of a vacuum filler assembly according to an embodiment of the invention illustrating a laterally translatable shroud assembly;

FIG. 7 is a side elevational view of the vacuum filler assembly disclosed in FIG; 6; and

FIG. 8 is a cross-sectional view taken along section line 88 in FIG. 6.

DETAILED DESCRIPTION Referring now to the drawings and particularly to FIGS. 14 thereof, one form of a vacuum filler apparatus of the present invention is shown.

Vacuum filler apparatus 11 includes a supply container 13 which is operably filled with finely divided particulate material. A delivery conduit 15 interconnects the supply container 13 with a vacuum filler head 17. The delivery conduit 15 is preferably provided internally with an auger feeding device (not shown) for transferring material from the container 13 to the filler head 17. While auger feeding is preferred, gravity or other feeding systems may also be utilized.

A sealing flange 19 is provided at the intersection of the conduit 15 with the container and serves to prevent both material loss and the entry of air into the conduit during the material transfer operation.

The vacuum filler head 17 is somewhat cylindrical and comprises two curved outer or exterior side walls 21 which extend longitudinally. The side walls 21 exhibit a generally elliptical configuration when viewed in cross section (note FIG. 2). Interiorly spaced from outer side walls 21 are inner walls 25 (note FIG. 3).

The inner walls 25 are supported at their ends by longitudinally extending partitions or spacer plates 29. The spacer plates 29 extend between a top surface 31 and a bottom surface 33 of the filler head 17 and between the outer side walls 21 and the inner walls 25. The inner walls 25, outer walls 21, partition 29, and top and bottom surfaces 31 and 33 define two chamber halves 27 and 28 which may be selectively connected to a vacuum or relief source.

A material receiving chamber or passageway 35 is provided in a central area of the head 17 between the inner walls 25. This chamber opens downwardly for transmitting material to an open mouth bag 69 attached thereto in accordance with the invention.

In this connection, the open mouth bags 69 are preferably constructed of Kraft paper which has been rendered vaPor proof by laminating tar paper or a polyethylene liner. The bags 69 are also constructed with gusset edges 71 as specifically illustrated in FIG. for ease of closing and sealing.

The filling head 17 dispenses and compacts the finely divided particulate material by removing interstitial air from between the particles as the material falls through the head.

The delivery conduit intersects the head 17 through one of the end flanges 29, note FIG. 3, and opens into the chamber 35. The delivery of material, however, does not disturb the integrity of the chambers 27 and 28. Thus, the chambers 27 and 28 are maintained separate and independent by the connecting walls 29 and the top and bottom surfaces 31 and 33.

The inner walls are provided with perforations or orifices 26 which provide a fluid communication path between the chambers 27 and 28 and the central chamber 35. A pair of screen members 37 and 39 are designed to conform to the exterior surface of the inner walls 25 and are suitably attached thereto. The screens cover the perforations 26 and act as a filter.

The perforated walls 25 and the screens 37 and 39 combine to form a longitudinally extending interior screen means coaxially disposed within the interior of the shell walls 21. This generally cylindrical screen means, as previously noted, forms a volume defining passage through which the finely divided particulate material is dispensed. In a preferred embodiment this screen means has a generally elliptical cross sectional configuration as does the outer shell 21.

Conduits 4la-43a, and 41b-43b are in fluid communication with chambers 27 and 28, respectively, and are attached to relief and vacuum sources 45 and 47, respectively.

In an operational mode, air is withdrawn through conduits 43a and 43b from first one side and then the other of the divided filling head with a time interval therebetween in which air is permitted to flow through relief conduits 41a and 41b, thus backflushing and cleaning the screens 37 and 39 of powder or other material that may have accumulated thereon. By alternating the vacuum and relief pressure on opposite sides of the head, a rapid and uniform filling operation may be achieved, as more fully discussed hereinafter.

Conventional valves 42 and 44 are positioned in vacuum lines 43a and 43b, respectively, to control the selective application of a vacuum from a source 47 which is alternately applied to the chambers 27 and 28. Also valves 46 and 48 are positioned in relief lines 41a and 41b, respectively, for selective control relief pressure from source 45 to clean the screens.

Referring again to FIG. 1, a pair of support members 49 are secured by welding or any other suitable connecting means to a top surface 31 of the filler head. The support members are equally spaced across the width of the generally elliptical shaped head 17 and protrude somewhat over the edges thereof. The members 49 are providedwith downwardly projecting tabs 51 having apertures 53 extending therethrough. Shafts 55 extend between the tabs 51 and are pivotally journalled therein. Journalled about the shafts 55 are spacer bushings 56 having downwardly extending shroud braces 57 attached thereto. The shroud braces are arranged in generally mutually parallel pairs. Also attached to the bushings 57 are linkages 61 which extend generally upwardly therefrom at an angle that is fixed relative to the braces 57. Therefore, movement of linkages 61 will pivot the braces 57 about the generally horizontal axis of the shaft 55. The braces 57 thus are vertically pivotable about generally horizontal axes defined by the shafts 55. I

Suitably attached to the braces 57 are clam shell shroud halves 63 which when closed form a bag enclosing shroud 64. Each of the shroud halves 63 includes generally curved complementary jaws 65 which conform to the shape of the filler head 17 and are selectively engageable thereagainst. Each shroud half also includes outwardly extending flange sections 67 for clamping the folded portions 71 of gusset type open mouth paper bags 69, as shown -in FIG. 5. The gusset type edges 71 are clamped between flange sections 67 when the shroud halves are closed (FIG. 1).

In the event the gusset portions are not firmly pressed together, air may seep into the bag and detract from the vacuum densifying operation. In order to minimize this possibility, a resilient gasket-like material 73 is provided along the facing complementary surfaces of the clamping jaws 65 and the flanges 67. This material 73 may comprise rubber of sufficient depth to provide adequate resiliency when the jaws and flanges are moved into abutting sealing engagement with the bag 69 (FIG. 1).

The shroud 64 extends downwardly from the bag mouth area to completely surround the bag in a clam shell posture. It will be appreciated that the shroud preferably avoids contacting or pinching a lower portion of the bag during the clamping operation. The bulbous configuration of the shroud contributes to this non-interfering clamping. Once. the clam shell shroud is closed, as shown in FIGS. 13, the bag is fully suspended from the open top thereof clamped at the lower end of the filler head 17.

The shroud, while surrounding the bag, as noted, does not interfere with the free filling thereof. To this end, a space 77 is maintained around the bag so that the bag may expand freely during the filling operation.

The clam-type shroud portions 63 are also provided with peripheral sealing means 79Wl'llCh include abutting flanges having a suitable sealing material therebetween. Thus, when the shroud portions close about the bag 69 and tightly hold the mouth thereof against the filler head 17, a seal is effected around the bag also.

Vacuum means 81 including conduits 83 are connected in fluid communication with each shroud portion'63. A vacuum may thus selectively be drawn on the volume formed between the inner surface of the closed clam shell halves, thus keeping the bag open during the vacuum filling operation. Means 82 for providing relief on the volume between the inner surfaces of the clam shell halves is suitably provided so that when the filling operation is completed the shell halves may be readily opened.

To effect closing of the shroud portion 63, a power means is connected to the linkages 61 which serves to pivot the braces 57 and the shroud portions secured thereto about the shafts 55. The power means may be of any conventional type. In this connection, an actuator including a cylinder 87 is pivotally mounted at 89. A piston assembly 91 is slidably-positioned within the cylinder and is pivotally mounted to an opposite linkage at 93. Hydraulic fluid supply lines 95 are in communication with the cylinder 87 at positions in front of and behind an internal piston.

The extended position of the piston assembly 91, as in FIG. 1, urges the linkages 61 outwardly and causes them to pivot and tightly clamp the bag to the filler head and close the shroud. Application of hydraulic fluid behind the piston will draw the linkages 61 toward one another and cause the shroud halves to open by pivoting generally, upwardly, and outwardly (FIG. 4).

The vacuum filler apparatus of FIGS. 1-4 also preferably includes a bag supporting roller platform and a transfer system including a power device which may weight the bag as it is being filled and thus automatically control the filling operation. These units are identical with and specifically described and illustrated in FIGS. 6-8 in connection with a linearly movable shroud arrangement to be discussed immediately hereafter.

Referring now to FIGS. 6-8, there is shown an alternative preferred embodiment of a vacuum filling apparatus 103 for filling open mouth bags. A support frame 105 holds the apparatus and includes vertical column members 107 extending upwardlyfrom a base 109. Substantially horizontally extending supports 111 project outwardly from an upper end of the members 107 and serves to hold a vacuum filler head 113 in position.

The filling head 113 has an elliptical cross-sectional configuration similar to that of the previously described head 17. Vacuum, vacuum relief, and material supply lines may also be provided in a manner similar to that shown in FIG. 1. Alternatively, a vacuum, vacuum relief and material supply system such as particularly described in applicants U.S. Pat. No. 3,605,826, FIGS. 5 and 6, may also be utilized. The relevant disclosure of applicants U.S. Pat. No. 3,605,826 is hereby incorporated by reference as though set forth at length.

A pair of semi-elliptical shroud members 121 are positioned for linear translating movement toward and away from one another by means of a pair of power actuator means 123 comprising piston assemblies 125 connected to each shroud half. A pair of cylinder assemblies 127 are opposingly fastened to a portion of the support frame 105 at locations 129.

The shroud members include an upper sealing portion 131 having a configurationsimilar to the previously described flanges 69. A bag 133 hangs downwardly from the sealing portion 131. A sealing assembly 135 is also provided at a lower portion of each shroud half and seals the shroud to a platform means 139.

A power device 141, which may, for example, be a pneumatic cylinder, is operable to raise and lower the platform assembly into a bag supporting position. Additionally, this power device 141 may include a pneumatic scale, not shown, which may indicate the loading condition of the bag in order to control the flow of particular material through line 119.

The platform assembly 139, includes a plurality of bag support rollers 143. The rollers 143 are arranged in a V-shaped cross-sectional posture to accommodate a.

OPERATION Referring now to the embodiment depicted in FIGS. 1-4, initially the shroud halves 63 are pivoted into an open posture by actuator 87 (see FIG. 4). The bag 69 is generally received in a folded condition and the mouth thereof must first be opened before being fitted around the head 17. The open mouth portion of a bag 69 is then slid upwardly to surround the filler head 17. It will be appreciated that the paper bag has a tendency to keep it folded shape and thus fits snugly about the filler head prior to the filling thereof. The remaining portion of the bag 69 hangs downwardly from the mouth and generally maintains a collapsed posture. The gusset type edges 71 of the bag are positioned so as to be generally aligned with the partitions 29 for subsequent clamping between the flanges 67.

The shroud portions are then pivoted into a closed position (FIG. 1). The closing of the shroud serves to tightly clamp the mouth of the bag against the periphery of the head and also presses the gusset portions of the bag against one another and. between flanges 67. The shroud periphery simultaneously seals about the remainder of the bag hanging downwardly from the clamped mouth.

The elliptical cross-sectional configuration of the head 17 minimizes the possibility of stress and thus tearing of the impervious, non-stretchable bag during the clamping and sealing operation. in this connection, as the shroud halves 63 are vertically pivoted about horizontal axes, the mouth of the'bag is uniformly and simultaneously peripherally clamped against the outer periphery of the filler head.

A vacuum is then applied via conduits 83 to the volume between the outer surface of the shroud to outwardly expand the bag within the bulbous shroud.

In the alternative embodiment illustrated in FIGS. 6-8, the bag 133 is fitted on the elliptical filler head 113 in a manner similar to that previously described with reference to the head 17. The shroud halves 121, however, are moved toward one another linearly by power actuators 123. Simultaneously, the platform assembly 139 is moved upwardly in a bag supporting position. The sealing means 131 clamps and seals the bag to the filler head 113. Sealing of the lower portion of the shroud 121 to the platform assembly 139 is accomplished by the sealing means 135, which may comprise a resilient material such as rubber.

The following description of the actual filling operation, while directed toward one embodiment of FIGS. 1-4, is also illustrative of a filling operation utilizable with the embodiment of FIGS. 6-8, with slight modification.

Once mounted in position, the bag is vacuum filled through the filler head to remove interstitialair from the particles of the finely divided particulate material as the impervious bag is filled. The material is thus dispensed into the bag in a compacted condition. More specifically, as discussed in US. Carter Pat. No. 3,605,826, the following filling procedure has been found to be suitable for co-operation with the shroud configurations of the invention. This vacuum filling sequence, however, is not intended to be exclusive.

After the shroud is sealed against the filling head 17, a vacuum is created in the bag 69 by selective operation of the vacuum source 47 and vacuum valves 42 and 44 in conduit portions 43a and 43b, respectively, and in the space between the interior periphery of the shroud 63 and the exterior periphery of the bag 69 by opening the vacuum source 81 in the vacuum conduit 83.

When the vacuum in and around the bag 69 has rea ched apredetermined value, preferably betweenTfi and 25 inches of mercury, valve means within the material supply conduit 15 opens for a predetermined and controlled period, and a first predetermined amount of particulate material is dispensed into the bag 69. The vacuum source 47, as noted, is arranged to alternate between the independent chambers 27 and 28 by alternate application of valves 42 and 44 placed in lines 43a and 43b. The first vacuum period may, for example, be supplied into chamber 27 by appropriate action of valve 44. After the initial cycle is complete a vacuum is drawn on the alternate chamber 28, by action of valve 42. The relief valve 46 then is opened for a period of time sufficient to drop the vacuum in the container interior to about to inches of mercury, thereby causing a flow of air into the container through the screens 37 and 39 in chamber 27 of the filling head 17. Therefore, particulate material which has accumulated on screens 37 and 39 will be flushed away. The momentary flow of air through the screens for cleaning purposes is preferably always insufficient to drop the vacuum in the bag 69 to zero vacuum, i.e., at atomospheric pressure.

After the relief source 45 has been closed for a sufficient time to permit recovery of the vacuum in the container, preferably to a value between 10 and 25 inches of mercury, the conduit 15 again dispenses a predeter mined amount of material into the bag 69. When the second predetermined amount of material has been dispensed, the material supplyis again stopped as is the vacuum source on chamber 28. The valve 42 communicating with chamber 27 is then opened and the relief valve 48 communicating with chamber 28 is opened long enough to drop the vacuum in the container to about 5 to 10 inches of mercury to clean the screens 37 and 39 on side 28 of the head in the manner previously described.

This alternate operation of the chambers 27 and 28 on either side of the head 17 is continued until a predetermined weight of materiaLas determined by a weight responsive device (not shown), is dispensed.

A relief pressure is then applied on both chambers 27 and 28 in the filling head 17 and the shroud halves 63. The power means 87 is then actuated to open the shroud halves 63 and, simultaneously as the seal between the shroud halves is broken, the platform 99 moves upwardly to support the filled bag thereon.

The platform 99 may then move to a down position, to gently lower the bag out of engagement with the head 17. A conveyor (not shown) may then be utilized to transport the full container away while another device may simultaneously deliver an empty bag for opening and placement over the filler head 17.

SUMMARY OF MAJOR ADVANTAGES From the foregoing, it can be seen that a simple yet effective clamping shroud is provided to hold and surround an impervious open mouth bag during a vacuum filling operation.

Of particular importance is the lateral translating movement of an embodiment wherein the shroud halves both clamp the bag against the head and provide a seal against a vertically positionable platform which supports a loaded bag and facilitates its discharge.

Also of significance is the simultaneous clamping and sealing functions performed by the downwardly pivotal clam-type shroud for uniform, and simultaneous peripheral engagement about the bag mouth.

Of additional importance are the clamping jaws which hold the mouth of the bag firmly against the filler head. Also the cooperating flanges advantageously press the gusset type ends of the paper bags firmly together during the filling thereof, the remainder of the shroud being spaced from the clamping jaws and flanges to allow for unhampered expansion of the bag as it is filled.

Also, significantly, the gusset type edges of an open mouth paper bag are clamped to a vacuum filling head minimizing stress on the bag adjacent to the gusseted edges.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than by the foregoing description, and allv changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is: I

1. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising:

vacuum filler head means forw-ithdrawing interstitial air from between particles of the finely divided,

particulate material during the operation of filling an impervious open mouth bag with the finely divided particulate material; and

a shroud means including,

means for clamping and sealing to said vacuum filled head means the open mouth of the impervious bag to be filled with the finely divided particulate material, I

a shell connected to' said means for clamping and sealing for surrounding the imperforate bag to be filled with finely divided particulate material including,

a pair of opposing shell halves movable to a closed position wherein said opposing shell halves surround the impervious bag to be filled and to an open position wherein said opposing shell halves are spaced from the impervious bag to be filled,

seal means extending about the periphery of said shell halves for providing an air seal therebetween when said shell halves are brought together in a closed position, means connected to at least one of said shell halves for drawing a vacuum on the volume formed between the inner surface of said shell halves in the closed position and the outer surface of the impervious bag to be filled with finely divided particulate material to expand the bag during the filling operation,

means for providing relief for the volume between the inner surface of said shell in the closed position and the outer surface of the impervious bag to be filled with particulate material upon completion of the filling operation.

2. The apparatus for vacuum filling an impervious open mouth bag as defined in claim 1 and further comprising:

means for linearly moving said opposing shell halves into a closed posture.

3. The apparatus for vacuum filling an impervious open mouth as defined in claim 1 and further comprismg:

means for generally vertically pivoting said shell halves about generally horizontal axes into a closed posture. i

4. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising:

vacuum filler head means for withdrawing interstitial air from between particles of the finely divided,

particulate material during the operation of filling an impervious open mouth bag with the finely divided particulate material; and

a shroud connected to said vacuum filler head means including,

means for clamping and sealing to said vacuum filler head means the open mouth of the impervious bag to be filled with the finely divided particulate material,

a clam shell connected to said means for clamping and sealing for surrounding the imperforate bag to be filled with finely divided particulate material including,

a pair of opposing clam shell halves lateraly translatable to a closed positionwherein said opposing clam shell halves surround the impervious bag to be filled and to an open position wherein said opposing clam shell halves extend away from the impervious bag to be filled,

seal means extending about the periphery of said clam shell halves for providing an air seal therebetween when said clam shell halves are translated together in a closed position;

means connected to at least one of said clam shell halves for drawing a vacuum on thevolume formed between the inner surface of said clam shell halves in the closed position and the outer surface of the impervious bag to be filled with finely divided particulate material to expand the bag during the filling operation,

means for providing relief for the volume between the inner surface of said clam shell in the closed position and the outer surface of the impervious bag to be filled with particulate material upon completion of the filling operation.

5. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4, wherein said means for clamping and sealing includes:

clamping flange means for pressing gusset type end edges of the impervious bag against one another thereby sealing the end edges of the bag during the filling operation.

6. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 5 wherein said vacuum filler head means is formed having:

a generally elliptical cross-sectional configuration for snugly accommodating without tearing the open mouth of an impervious bag having gusset type edges during the filling operation.

7. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4 and further comprising:

power means connected to said clam shell halves for mechanically laterally translating said clam shell halves between the open and closed position.

8. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4 wherein said vacuum filler head means comprises:

a generally cylindrical exterior shell,

a generally cylindrical screen coaxially disposed coextensive within and spaced from said shell,

the interior volume of said generally cylindrical screen forming a passage for'dispensing the finely divided particulate material into the impervious bag,

a pair of longitudinally extending partitions connected between said generally cylindrical exterior shell and'said generally cylindrical screen to form therebetween a pair of separated chambers;

at least one vacuum conduit and one relief conduit connected in fluid communication to each of said separated chambers; and

means for selectively controlling fluid flow through said conduits.

9. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 8 wherein said generally cylindrical exterior shell is formed having:

a substantially elliptical cross-section configuration for snugly accommodating without tearing the open mouth of the impervious bag having gusset type edges during the filling operation.

10. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising: 1

a filler head having a generally elliptical crosssectional configuration, said filler head including, a longitudinally extending exterior shell,

a longitudinally extending interior screeen coaxially disposed within the interior of said exterior shell and having a central opening therein for the passage of finely divided particulate material therethrough, and

partition means extending between the exterior shell and the interior screen for dividing the volume between the exterior shell and the interior screen into separate chamber-halves, each of said chamber halves being provided with, means for selectively drawing a vacuum within the chamber halves, and means for selectively providing relief within the chamber halves;

shroud means operably connected to said filler head for clamping an impervious open mouth bag to said filler head during a filling operation, and for sea]- ingly surrounding the bag during the vacuum filling operation, and

means connected to said shroud means for selectively connecting a vacuum source to said shroud for evacuating the volume between the bag and said shroud means during the vacuum filling operation.

11. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material according to claim 10 wherein said shroud means include:

outwardly extending flange sections for sealingly clamping gusseted end edges of the impervious bag between said flange sections during the vacuum filling operation.

12. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 10 wherein'said shroud comprises:

a pair of clam shell halves vertically pivotable about a generally horizontal axis and having complementary sealing edges thereabout, said halves having a bulbous central portion defining a bag receiving volume.

13. An apparatus for filling an impervious open mouth bag with finely divided particulate material comprising:

a filling head for dispensing and compacting finely divided particulate material, including two independent chambers connected together to provide a finely divided particulate material passage therebetween each of said chambers being operably connected with means for selectively providing a vacuum within said chamber and means selectively providing relief within said chamber;

a shroud having,

a clamping portion including,

generally curved complementary jaws engageable with said filler head for clamping the open mouth of the impervious bag about said filling head and outwardly extending clamping flanges for closing gusseted end edges of the impervious bag to be filled and said shroud having; peripheral sealing means spaced from the impervious bag for providing an airtight seal about the bag during the vacuum filling thereof;

vacuum means connected to said shroud for selectively applying a vacuum about the clamped bag thereby expanding the bag within said shroud during the vacuum filling operation; and

vacuum relief means connected to said shroud for selectively relieving the vacuum about the bag following the vacuum filling operation.

14. A method of vacuum filling an impervious open mouth bag with finely divided particulate material comprising the steps of:

surrounding a filler head with the open mouth portion of an impervious bag to be filled, the remaining portion of the bag extending downwardly therefrom,

enclosing the bag within a shroud including the steps clamping the mouth of the bag against the outer periphery of the filler head, and

substantially simultaneously bringing together a pair of shells to enclose the bag within a shroud;

applying a vacuum to the volume between the outer surface of the bag and the inner surface of the shroud to outwardly expand the bag within the shroud; and

vacuum filling the bag through the filler head to remove interstitial air from between particles of the finely divided particulate material as the impervious bag is filled with the particulate material.

15. The method of vacuum filling an impervious open mouth bag with finely divided particulate material according to claim 14 wherein said bringing together step includes:

linearly moving a pair of shells toward one anotherto enclose the bag clamped to the filling head and enclosed within a shroud, said shells forming a seal with a platform vertically positionable into supporting relationship with the bag.

16. The method of vacuum filling an impervious open mouth. bag was finely divided particulate material according to claim 15 wherein said bringing together step includes:

vertically pivoting about a generally horizontal axis,

a pair of clam shells to enclose the bag within a shroud.

17. A method for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 16 wherein said step of vacuum filling comprises the steps of:

creating a vacuum behind a first laterally extending internal screen surface of the filler head;

creating a vacuum behind a second laterally extending internal screen surface of the filler head;

erally extending internal screen surface and the second laterally extending internal screen surface to back flush the second lateral extending internal screen surface.

18. A method for vacuum-filling an impervious open mouth bag with finely divided particulate material as defined in claim 17 and further comprising the step of:

interrupting the flow of finely divided particulate material into the impervious bag prior to each back flushing operation. 

1. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising: vacuum filler head means for withdrawing interstitial air from between particles of the finely divided, particulate material during the operation of filling an impervious open mouth bag with the finely divided particulate material; and a shroud means including, means for clamping and sealing to said vacuum filled head means the open mouth of the impervious bag to be filled with the finely divided particulate material, a shell connected to said means for clamping and sealing for surrounding the imperforate bag to be filled with finely divided particulate material including, a pair of opposing shell halves movable to a closed position wherein said opposing shell halves surround the impervious bag to be filled and to an open position wherein said opposing shell halves are spaced from the impervious bag to be filled, seal means extending about the periphery of said shell halves for providing an air seal therebetween when said shell halves are brought together in a closed position, means connected to at least one of said shell halves for drawing a vacuum on the volume formed between the inner surface of said shell halves in the closed position and the outer surface of the impervious bag to be filled with finely divided particulate material to expand the bag during the filling operation, means for providing relief for the volume between the inner surface of said shell in the closed position and the outer surface of the impervious bag to be filled with particulate material upon completion of the filling operation.
 2. The apparatus for vacuum filling an impervious open mouth bag as defined in claim 1 and further comprising: means for linearly moving said opposing shell halves into a closed posture.
 3. The apparatus for vacuum filling an impervious open mouth as defined in claim 1 and further comprising: means for generally vertically pivoting said shell halves about generally horizontal axes into a closed posture.
 4. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising: vacuum filler head means for withdrawing interstitial air from between particles of the finely divided, particulate material during the operation of filling an impervious open mouth bag with the finely divided particulate material; and a shroud connected to said vacuum filler head means including, means for clamping and sealing to said vacuum filler head means the open mouth of the impervious bag to be filled with the finely divided particulate material, a clam shell connected to said means for clamping and sealing for surrounding the imperforate bag to be filled with finely divided particulate material including, a pair of opposing clam shell halves laterally translatable to a closed position wherein said opposing clam shell halves surround the impervious bag to be filled and to an open position wherein said opposing clam shell halves extend away from the impervious bag to be filled, seal means extending about the periphery of said clam shell halves for providing an air seal therebetween when said clam shell halves are translated together in a closed position; means connected to at least one of said clam shell halves for drawing a vacuum on the volume formed between the inner surface of said clam shell halves in the closed position and the outer surface of the impervious bag to be filled with finely divided particulate material to expand the bag during the filling operation, means for providing relief for the volume between the inner surface of said clam shell in the closed position and the outer surface of the impervious bag to be filled with particulate material upon completion of the filling operation.
 5. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4, wherein said means for clamping and sealing includes: clamping flange means for pressing gusset type end edges of the impervious bag against one another thereby sealing the end edges of the bag during the filling operation.
 6. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 5 wherein said vacuum filler head means is formed having: a generally elliptical cross-sectional configuration for snugly accommodating without tearing the open mouth of an impervious bag having gusset type edges during the filling operation.
 7. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4 and further comprising: power means connected to said clam shell halves for mechanically laterally translating said clam shell halves between the open and closed position.
 8. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 4 wherein said vacuum filler head means comprises: a generally cylindrical exterior shell, a generally cylindrical screen coaxially disposed coextensive within and spaced from said shell, the interior volume of said generally cylindrical screen forming a passage for dispensing the finely divided particulate material into the impervious bag, a pair of longitudinally extending partitions connected between said generally cylindrical exterior shell and said generally cylindrical screen to form therebetween a pair of separated chambers; at least one vacuum conduit and one relief conduit connected in fluid communication to each of said separated chambers; and means for selectively controlling fluid flow through said conduits.
 9. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 8 wherein said generally cylindrical exterior shell is formed having: a substantially elliptical cross-section configuration for snugly accommodating without tearing the open mouth of the impervious bag having gusset type edges during the filling operation.
 10. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material comprising: a filler head having a generally elliptical cross-sectional configuration, said filler head including, a longitudinally extending exterior shell, a longitudinally extending interior screen coaxially disposed within the interior of said exterior shell and having a central opening therein for the passage of finely divided particulate material therethrough, and partition means extending between the exterior shell and the interior screen for dividing the volume between the exterior shell and the interior screen into separate chamber halves, each of said chamber halves being provided with, means for selectively drawing a vacuum within the chamber halves, and means for selectively providing relief within the chamber halves; shroud means operably connected to said filler head for clamping an impervious open mouth bag to said filler head during a filling operation, and for sealingly surrounding the bag during the vacuum filling operation, and means connected to said shroud means for selectively connecting a vacuum source to said shroud for evacuating the volume between the bag and said shroud means during the vacuum filling operation.
 11. An apparatus for vacuum Filling an impervious open mouth bag with finely divided particulate material according to claim 10 wherein said shroud means include: outwardly extending flange sections for sealingly clamping gusseted end edges of the impervious bag between said flange sections during the vacuum filling operation.
 12. An apparatus for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 10 wherein said shroud comprises: a pair of clam shell halves vertically pivotable about a generally horizontal axis and having complementary sealing edges thereabout, said halves having a bulbous central portion defining a bag receiving volume.
 13. An apparatus for filling an impervious open mouth bag with finely divided particulate material comprising: a filling head for dispensing and compacting finely divided particulate material, including two independent chambers connected together to provide a finely divided particulate material passage therebetween each of said chambers being operably connected with means for selectively providing a vacuum within said chamber and means for selectively providing relief within said chamber; a shroud having, a clamping portion including, generally curved complementary jaws engageable with said filler head for clamping the open mouth of the impervious bag about said filling head and outwardly extending clamping flanges for closing gusseted end edges of the impervious bag to be filled and said shroud having; peripheral sealing means spaced from the impervious bag for providing an airtight seal about the bag during the vacuum filling thereof; vacuum means connected to said shroud for selectively applying a vacuum about the clamped bag thereby expanding the bag within said shroud during the vacuum filling operation; and vacuum relief means connected to said shroud for selectively relieving the vacuum about the bag following the vacuum filling operation.
 14. A method of vacuum filling an impervious open mouth bag with finely divided particulate material comprising the steps of: surrounding a filler head with the open mouth portion of an impervious bag to be filled, the remaining portion of the bag extending downwardly therefrom, enclosing the bag within a shroud including the steps of, clamping the mouth of the bag against the outer periphery of the filler head, and substantially simultaneously bringing together a pair of shells to enclose the bag within a shroud; applying a vacuum to the volume between the outer surface of the bag and the inner surface of the shroud to outwardly expand the bag within the shroud; and vacuum filling the bag through the filler head to remove interstitial air from between particles of the finely divided particulate material as the impervious bag is filled with the particulate material.
 15. The method of vacuum filling an impervious open mouth bag with finely divided particulate material according to claim 14 wherein said bringing together step includes: linearly moving a pair of shells toward one another to enclose the bag clamped to the filling head and enclosed within a shroud, said shells forming a seal with a platform vertically positionable into supporting relationship with the bag.
 16. The method of vacuum filling an impervious open mouth bag was finely divided particulate material according to claim 15 wherein said bringing together step includes: vertically pivoting about a generally horizontal axis, a pair of clam shells to enclose the bag within a shroud.
 17. A method for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 16 wherein said step of vacuum filling comprises the steps of: creating a vacuum behind a first laterally extending internal screen surface of the filler head; creating a vacuum behind a second laterally extending internal screen surface of the filler head; withdrawing air from within the Interior of the bag and the filler head through the first and second laterally extending internal screen surfaces; dispensing finely divided particulate material through the filler head into the bag and simultaneously withdrawing interstitial air from between the particles of the finely divided particulate material as the particulate material passes through the filler head; alternately and intermittently reducing the vacuum behind the first laterally extending internal screen surface of the filler head to back flush the first laterally extending internal screen surface and the second laterally extending internal screen surface to back flush the second lateral extending internal screen surface.
 18. A method for vacuum filling an impervious open mouth bag with finely divided particulate material as defined in claim 17 and further comprising the step of: interrupting the flow of finely divided particulate material into the impervious bag prior to each back flushing operation. 